1 From the main car park, go past the tourist information centre then go left along Church Street. At the crossroads in the centre of town turn right to head up Broad Street, which later becomes High Street.

2 When you get to a point just beyond the town hall, turn left past a small car parking area and pass through the impresive wrought iron gates of the Powis Castle Estate. Now follow the tarmac drive through the park grounds and past Llyn Du (which means the black lake in English).

3 Take the right fork, the high road, which leads to the north side of the castle. You can detour from the walk here to visit the world-famous gardens and the castle with its fine paintings and furniture and works of Indian art collected by Robert Clive. Continue on the walk on the high road and follow it past two more pools on the left and the Ladies Pool on the right to reach a country lane.

4 Turn left along the country lane. Opposite the next estate entrance leave the lane for a path on the right which follows a dirt track across a field. The track turns left over a bridge and into another field. Here you follow a fence on the right and cut diagonally across the fields to a step stile in the far corner. Over this a clear sunken grass track continues across another field to reach a country lane close to the Montgomery Canal. The canal, which runs for 33 miles (53km) from Welsh Frankton in Shropshire to Newtown in Powys, is gradually being restored. You may see a number of narrowboats cruising along this section.

5 Turn left along the lane before taking a path on the left which descends to the canal tow path at Belan Locks. Head north along the canal, passing close to some half-timbered cottages. Pass the Powysland Museum and Canal Centre, with its exhibits of local agriculture and crafts and the canal and railway systems, to reach the wharf and aqueduct at Welshpool. Turn left here along the tarred path to return to the car park.

A prosperous and bustling market town set amid rolling green hills, wood and hedgerows, Welshpool has always been synonymous with the River Severn, which flows through it. It was the Severn that brought trade to the town, for it was navigable by boat. The town was, until 1835, known as Pool and some of the old mileposts still refer to Pool. The 'Welsh' was added to distinguish the place from Poole in Dorset.

When you walk up the busy High Street today you'll notice the fine architecture, most of it Georgian, like the Royal Oak Hotel, but also many older half-timbered buildings. Almost every tourist who comes to Welshpool comes to see the fine castle of Powis. On this route you turn off through the impressive wrought-iron gates before strolling along the long drive through the estate's parklands. Proud oaks are scattered on the well-mown grasslands and a majestic scene is set when you see deer roaming among the trees, maybe antlered stags, or those cute little fallow deer.

Today the castle is a grand red mansion, with castellated ramparts, tall chimneys, rows of fine leaded windows and 17th-century balustraded terraces looking over manicured lawns and neatly clipped yews. Lead statues of a shepherd and shepherdess survive from those early days and keep watch over the colourful shrubs and perennial borders.

However, the scene would have been so different in 1200, when the castle was first built for the warring Princes of Powys. The battlements would have been there, but there would have been no elegant windows or pretty gardens, for this place was designed to repel enemies, both English and Welsh: more often than not Powis sided with the English, even against the Glyndwr rebellion. The fact that Powis has been continuously occupied has meant that it has made a successful transition from fortress to a comfortable grand mansion.

In 1587 the powerful Herbert family, who became the Earls of Powis, took possession of the castle. They were to reside here until 1988, when the 6th Earl died, and were responsible for the transition. Only for a brief period, when they were attacked by Cromwellian forces and replaced by their bitter rivals, the Myddletons of Chirk, were the Royalist Herberts displaced.

On leaving the castle behind, you are in rural Wales and you descend to the tow path of the Montgomery Canal at the Belan Locks. Built by three different companies and opened in stages from 1796, the canal was designed for narrowboats. Today it is a quiet backwater and a pleasant return route to the wharf at Welshpool.

Where to eat and drink

At Peppers you'll find a wide variety of coffees and beverages to go with the home-made cakes and light meals - the rich chocolate fudge cake has been declared 'wicked'. If you want a pub meal, try the Royal Oak in the High Street. This 300-year-old coaching inn has the Acorn Family Café and Restaurant for light meals or the Oak and Ostler Bars for meals and fine cask ales.

While you're there

You could take a trip on the Welshpool and Llanfair Railway, another one of those great little narrow-gauge steam railways of Wales. Pulled by engines from places like Sierra Leone and Austria, the train steams its way through the verdant valley of the Afon Banwy to Llanfair Caereinion. It's open at weekends between March and December and on most days in June, July and August.

What to look for

The lack of recent activity in the canal has allowed several interesting plant species to grow here such as floating water plantain with its white buttercup-like flowers with yellow spots - it blooms between May and August. The perennial plant's surface leaves are elliptical while those underwater are narrow and tapering. You may also see the scarce frogbit, another floating perennial with similar pearly white flowers and bronze-tinged green kidney shaped leaves.